Thermostat



FIG. 1 is a front elevational view of a thermostat showing my design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a front elevation of the thermostat shown with different unclaimed environmental structure.

The broken lines showing a display screen and temperature control buttons in FIGS. 1 and 6 are for illustrative purposes only and do not form part of the claimed design. 

The ornamental design for a thermostat, as shown and described. 